Protein Accumulation and Impaired Autophagy Underlie Cognitive Dysfunction in Angelman Syndrome

Abstract

Angelman syndrome (AS) is a genetic neurodevelopmental disorder that is accompanied by several neurological impairments including cognitive and intellectual disabilities, seizures, developmental delay, and others ( 1 Bird L.M. Angelman syndrome: Review of clinical and molecular aspects. Appl Clin Genet. 2014; 7: 93-104 Crossref PubMed Scopus (147) Google Scholar ). How the genetic abnormalities that cause AS result in these brain-related impairments remains unknown. Emerging work has revealed that AS is associated with elevated levels of activity-regulated cytoskeletal protein (ARC), which is an immediate-early gene (IEG) product that plays a critical role in driving learning-related synaptic plasticity ( 2 Pastuzyn E.D. Shepherd J.D. Activity-dependent arc expression and homeostatic synaptic plasticity are altered in neurons from a mouse model of Angelman syndrome. Front Mol Neurosci. 2017; 10: 234 Crossref PubMed Scopus (35) Google Scholar ). These elevated levels have been linked to deficits in various protein degradation pathways, one of which may involve the autophagy system. Importantly, autophagy is induced by learning and is required for long-term memory formation, which highlights it as a potential player in neurological impairments in AS. SEE CORRESPONDING ARTICLE ON PAGE 68 SEE CORRESPONDING ARTICLE ON PAGE 68 Excessive Protein Accumulation and Impaired Autophagy in the Hippocampus of Angelman Syndrome Modeled in MiceBiological PsychiatryVol. 94Issue 1PreviewAngelman syndrome (AS), a neurodevelopmental disorder caused by abnormalities of the 15q11.2-q13.1 chromosome region, is characterized by impairment of cognitive and motor functions, sleep problems, and seizures. How the genetic defects of AS produce these neurological symptoms is unclear. Mice modeling AS (AS mice) accumulate activity-regulated cytoskeleton-associated protein (ARC/ARG3.1), a neuronal immediate early gene (IEG) critical for synaptic plasticity. This accumulation suggests an altered protein metabolism. Full-Text PDF